Method of riveting



March 17, 1931. MCDONOUGH 1,796,852

METHOD OF RIVETING Filed May 31, 1927 Patented Mar. 17, 1931 UNITEDSTATES PATENT OFFICE JOHN MCDONOUGH, OF CHICAGO, ILLINOIS, ASSIGNOR TOWESTERN ELECTRIC COM- PANY, INCORPORATED, OF NEW YORK, N. Y., ACORPORATION OF NEW YORK METHOD or RIVETING Applicationfiled May 31,1927. Serial No. 195,379.

This invention relates to a method of riveting, and more particularly toa method of riveting pins in thin sheet materials.

Considerable difficulty has been experienced in riveting pins in thinsheet material due to a distortion of the sheet as the rivet expands andforces the material radially outward from the aperture in which therivet is set. This is apparently due to the fact that the thin sheetmaterial does not possess suflicient rigidity to retain the surroundingmaterial in its original plane when it is attempted to draw the metal ofthe sheet in the vicinity of the aperture. Objects of this invention areto provide a method of obviating difiiculties heretofore experienced andmaking it possible to rivet pins in thin sheet material withoutdistorting the sheet.

The invention contemplates the provision of a method in which the metalimmediately surrounding the aperture in the sheet metal is formed so asto extend out of the plane of the sheet as the rivet is expanded toavoid a radial expansion of the material in the plane of the sheet. Inaccordance with one embodiment of the invention, the metal of the pinbeing riveted is drawn in such a manner as to cause the sheet metaladjacent the aperture in which the pin is being riveted to be drawn outof the plane of the sheet.

It is believed that a complete understanding of the invention may be hadby reference to the following description taken in conjunction with theaccompanying drawing which illustrates one embodiment of the inventionas applied to attaching pins to calling dials for automatic telephones,in which Fig. 1 is a plan view of a die and its su port showing anunfinished dial partial y broken away in a position ready to be workedupon;

Fig. 2 is a fragmentary view of a riveting machine with a sectional viewof the die and its support taken on line 22 of Fig. 1;

Fig. 3 is an enlarged fragmentary sectional view through the center of arivet showing the rivet in a sheet of material at the beginning of theriveting operation, and

Fig. 4 is a view similar to Fig. 3 showing the rivet after the rivetingoperation.

Referring to the drawing in which the same reference charactersdesignate similar parts in the several views, a riveting machine isdesignated generally at 7 and comprises a bracket 8 upon which a diesupport 9 is rotatably mounted and held in position by a pin- 11 fixedin the bracket. An arm 12 of the machine carries a compressed aircylinder 13 for operating a reciprocating hammer 14 through the mediumof the compressed air which is supplied through a tube 15 from a sourceof compressed air (not shown). Inasmuch as any suitable compressed aircylinder and hammer may be employed they have not been shown in detail.

The die support 9 is provided with an annular groove 16 in which asimilarly shaped die 17 is carried. The die is made of an annular shapein the present instance for the reason that the embodiment of theinvention illustrated is adapted to rivet pins 10 in calling dials 18which have an annular shape as used in automatic telephone systems. Thedie is provided with three tubular holes 19 corresponding to the numberof pins to be riveted into a calling dial and each hole is surrounded atits upper end by a boss 21 having a slightly convex surface so as toform a shearing edge around the hole.

The pins 10 used in the riveting operation comprise a head 22, anenlarged portion which may be slightly tapered and ending in a shoulder24, and a straight reduced portion 25. In order to rivet the pins in acalling dial, a dial with three apertures provided therein is placed onthe die 17 in suclra position that the apertures in the dial coincidewith the tubular holes 19 in the die. A pin is placed in each hole withthe reduced portion inserted in the hole and the shoulder of theenlarged portion resting upon the boss 21. The die support is thenrotated until a pin is directly under the hammer, when com-. pressed airis admitted to the cylinder 13 by means (not shown) to cause thereciprocating hammer to perform the riveting operation. It will be notedthat in the beginning of the riveting operation the dial 18 as well asthe shoulder 24 of the pin rest upon the boss 21,

but when the shoulder is being sheared from r the straight portion it isalso turned outwardly and upset, thereby turning the edge of thematerial of the dial surrounding the aperture and bending the materialout of the plane of the dial as shown in Fig. 4 of the drawing. By thusbending the material out of the plane of the dial the distorting radialstrains adjacent the aperture in the dial are avoided when the pin isradially expanded in the riveting operation.

- It will be understood that the embodiment of the invention hereindescribed and illustrated is merely a convenient and useful form of theinvention, which is capable of many other modifications withoutdeparting from the spirit and scope of the invention.

WVhat is claimed is:

1. A method for riveting a shank to a thin sheet of metal, consisting inproviding a rivet having a reduced shank at one end, a head at the otherend, and an intermediate enlarged shank forming a shoulder between itand the reduced shank, providing a thin sheet of metal having anaperture, placing the rivet through the aperture, with the walls of theaperture closely embracing the enlarged shank at the shoulder, andshearing the metal of the enlarged shank substantially to the size ofthe reduced shank from the shoulder toward the head, as well asupsetting such sheared metal by forcing the shouldertoward a fixedshearing and upsetting zone, while re tarding the sheet from riding upthe enlarged shank, such upset metal as well as the metal to be shearedand upset being forced downwardly toward the sheet and outwardly head atthe other end and an intermediate enlarged shank forming a shoulderbetween the enlarged shank and the reduced shank in an aperture in thesheet material with the walls of the aperture closely engaging theenlarged shank at .the shoulder, shearing the metal of the enlargedshank substantially to the size of the reduced shank from the shouldertoward the head and upsetting the sheared metalv to cause a downward andoutward flow of the material of the rivet toward the reduced shank sideof the sheet to bulge the sheet material adjacent the aperture, enlargethe aperture and form a recess into which the rivet head is countersunk.

4. A method of securing a rivet in thin sheet metal which consists inproviding a rivet having a head, a reduced shank ortion and anintermediate enlarged an tapered shank portion, forming a shoulderbetween the enlarged and reduced shank portions, placing the rivet in anaperture in the sheet material with the walls of the aperture closelyembracing the enlarged shank portion adjacent the shoulder and theshoulder adjacent a shearing and upsetting zone, and applying pressureto the head of therivet to cause the material of the enlarged shank tobe sheared to approximately the size of the reduced shank and to beupset outwardly and downwardly forming a recess in the sheet materialand surroundingthe edges of the recess.

In witness whereof, I hereunto subscribe my name this 20th day of May A.D., 1927.

JOHN MCDONOUGH.

against the walls of the aperture and the reduced shank side of thesheet, whereby the friction of the downwardly moving shank, togetherwith the outward flow of upset metal at and below the aperture willbulge the sheet adjacent the aperture, enlarge the opening and form arecess.

2. A method of securing a rivet in a thin sheet of material having anaperture, which consists in placing a rivet having a reduced shank atone end, a head at the other end, and an intermediate enlarged shankforming a shoulder between it and the reduced shank in the aperture inthe sheet with the walls of the aperture closely embracing the enlargedshank and with the sheet closely adjacent the shoulder, shearing themetal of the enlarged shank substantially to the size of the reducedshank from the shoulder toward the head, and upsetting the sheared metalradially against the walls of the aperture while retarding the sheetfrom riding up the enlarged shank by forcing the shoulder toward a fixedshearing and upsetting zone to form a recess in the sheet material aboutthe aperture for receiving the head of the rivet.

3. A method of securing a rivet in thin sheet material, which consistsin placin a rivet having a reduced shank at one en a

